1. Field of the Invention
The present invention relates generally to optical devices with optoelectronic components for data transmission. More particularly, the present invention relates to optical subassemblies that incorporate transistor-outline (TO) cans having various internal components.
2. Related Technology
Recent trends in the advancement of optical data communications have resulted in smaller components and faster data transmission rates. While developers have been successful in producing smaller and faster optoelectronic transmitters, the reliability of smaller transmitters has been problematic. In part, this has resulted from the inherent problems associated with the intricate manufacturing techniques required to produce miniature transmitters that are functionally reliable. Thus, the percentage of inoperable miniature transmitters has increased as the size has decreased.
One consequence of increasing the probability that an optoelectronic transmitter will be inoperable is the drastic increase in manufacturing costs that have to be recouped by the operational transmitters. This is because some optoelectronic transmitters are at an advanced level of production or essentially complete before a functionality test, such as a burn-in, can be performed. As such, an inoperable transmitter may have expensive components installed before a determination can be made as to whether or not it will function as intended. In order for the manufacturer to avoid operating at a loss, the functional optoelectronic transmitters and the optical communication equipment in which they are utilized have to be priced to account for a certain percentage of inoperable devices.
One method of counteracting this problem has been to position certain components of an optoelectronic transmitter remote from the laser assembly, especially in transistor outline can (“TO-can”) devices. Briefly, a laser assembly, such as a laser diode, is disposed within the header of a TO-can. Size limitations of the TO-can however have necessitated the positioning of various optical and/or electrical components being external to the header can. This arrangement, in turn, causes other manufacturing difficulties. For example, positioning these components external to the header can cause electronic impedance and/or resistance matching problems that present a concern in view of the narrow margin of error associated with accurately driving the lasers. Also, other problems have arisen from the actual optical path being impeded by adhesives or other bonding materials used to attach optical components to the TO-can.